Heterogeneous ice nucleation induced by porous materials

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The nucleation of ice particles plays an important role for the formation of clouds and subsequent precipitation, with implications for atmospheric chemistry, cloud physics and Earth's climate. In order to quantify and predict the effects of clouds in weather forecast and climate.models, ice particle formation has to be described in a realistic manner. One of the most important fomiation mechanisms is heterogeneous ice nucleation in the immersion mode, in which ice is initiated at the surface of an ice nucleus - for example a mineral dust particle - immersed in an aqueous droplet. We will perform numerous immersion freezing experiments during this study. We will investigate the ice nucleation activity of various materials that occur in the form of aerosol particles in the atmosphere. In particular, we aim at quantifying the temperature and time dependence of the ice nucleation induced by them. A special focus will be on the systematic study of ice nucleation induced by porous materials. We want to investigate both, synthetic materials such as mesoporous silica as well as naturally occurring materials such as microporous zeolites.